1. Field of the Invention
The present invention relates to functional emulsions for use in food, drugs and cosmetics, etc.
2. Description of Related Art
Many products are manufactured and sold in a state of emulsion to make the products easier to eat and use as well as to extend the preservation term of the products. As examples, margarine and ice cream can be listed as food, ointment as drugs, and cosmetic cream as cosmetics.
Almost all the conventional emulsions are an oil-in-water (O/W) type or a water-in-oil type (W/O) in which water is used as a continuous phase and oil is used as a dispersed phase, and a water-in-oil-in-water (W/O/W) type or an oil-in-water-in-oil (O/W/O) type which is a combined type. Emulsions according to the present invention have not been studied yet.
At present polyphenols, such as catechin or the like, attract much attention as antioxidants. Almost all polyphenols are insoluble or have low solubility with respect to water. Therefore, so far, when polyphenols were applied in foods, drugs or cosmetics, it was impossible to present it in an emulsified form, or if it was possible, such form could not be kept for a long period of time, because phase separation occurred in a short time. Also, it was impossible to introduce polyphenols into emulsions at a high concentration.
In addition to polyphenol, many functional components, such as androstenedione which is known as a steroid hormone, taxol which is an anticancerous terpenoid, validamycin which is known as an agent for controlling sheath blight, or the like, are generally low in solubility with respect to water and oil. Therefore, since it is difficult to produce a dispersion system which contains these components in a high concentration and they must be used in a extremely low concentration, the efficiency is low and the range of viable applications for them is limited.
The present invention takes into consideration that a method of using a material insoluble or of low solublility with respect to water or oil as an emulsion dispersion system has not yet been established. According to the present invention, there is provided functional emulsions wherein a material being insoluble or having low solubility with respect to water and oil is dissolved in alcohol and the alcohol is dispersed in oil as a dispersed phase.
There is also provided functional emulsions wherein a material being insoluble or having low solubility with respect to water and oil is dissolved in alcohol, the alcohol is dispersed in oil as a dispersed phase, and the oil is dispersed in water as a dispersed phase.
As materials that is insoluble or has low solubility with respect to water and oil, polyphenols such as catechin, anthocyanin, quercetin or the like can be listed as materials having a relation to foods. Catechin and anthocyanin are known as polyphenols which are slightly soluble in water. However, many polyphenols, such as quercetin or the like, almost never dissolve in water. Some slightly dissolve in vegetable oil. In contrast, however, these materials show high solubility of around 20-30% with respect to alcohol such as ethanol or the like. Therefore, according to the present invention, it is possible to establish a stable dispersion system of a high concentration by dispersing such alcohol into oil.
In addition, as a material that is insoluble or has low solubility with respect to water and oil, androstenedione which is known as steroid hormone, taxol which is an anticancerous terpenoid, or validamycin which is known as an agent for controlling sheath blight can be listed. However, other functional components may be listed.
Any emulsifying agent (surfactant) is required to obtain emulsions by dispersing alcohol into oil. It is preferable to use nonionic polyglycerol fatty acid ester as such emulsifying agent. In more detail, tetraglycerol monoester (MO310), hexaglycerol monoester (MO500) or polyglycerol oleic acid ester (MO750: HLB12.9) can be listed as other such emulsifying agents.
As oil comprising a continuous phase of emulsions, vegetable oil is preferable and, specifically, triglyceride can be listed as an example of such.
As an alcohol, methanol, hydrous methanol, ethanol, hydrous ethanol, propanol, hydrous propanol, butanol or hydrous butanol is used. It is preferable to make the ratio of oil with respect to alcohol at least 8:2 by volume. When the ratio of alcohol as a dispersed phase is increased to above the preferable ratio, unwanted phase separation occurs readily.